Sensory Processing Patterns and Sleep Quality in Primary School Children

Objectives Sensory processing and sleep quality affect children's academic performance and their quality of life. This study aimed to investigate the relationship between sensory processing patterns and sleep quality in primary school children. Materials & Methods In this cross-sectional study, 231 primary school students aged 7 to 12 years old (133 girls and 98 boys, the mean age of 8.68±1.51) who were studying in schools in Tehran were randomly selected through cluster sampling. The researchers distributed a questionnaire on children's sleep habits to assess the quality of sleep and a sensory profile questionnaire to assess the sensory processing patterns (avoidance, sensitivity, seeking, and registration) among the students. Results In this study, we found a meaningful moderate relationship between sensory processing patterns and overall scores of sleep habits (p <0.001). Moreover, each of the sensory processing patterns had a negative relationship with areas of sleep habits (p = 0.005). There was also a significant difference between children who had more challenges with sleep maintenance and children with normal sleep patterns in sensory processing; mean differences were significant in all the four sensory quadrants (registration, seeking, sensitivity, and avoiding) (p <0.001). Conclusion The sensory processing patterns are moderately correlated with sleep habits in primary school children. Occupational therapists and other specialists working in the field of children's sleep should consider the relationship between sensory challenges and sleep habits while making decisions about sensory challenges and sleep problems. Better sleep may occur with attention to sensory needs in sleep routines. Better sleep may lead to improved quality of life in families and enhanced student performance at school.


Introduction
About 43% of school age children experience disruptions in sleep (1). A sleep problem is the fifth cause of referrals to physicians (2). According to the occupational therapy practice framework (OTPF), sleep is one of the areas of activity that supports active and healthy participation in other areas of life (3). Sleep is also considered a necessary prerequisite for children's function (4). Studies on children have indicated that poor sleep can lead to obesity (5,6), depression symptoms (7), attention deficit-hyperactivity disorder (8), and poor neurobehavior function (9). Moreover, researchers have shown that sleeping problems at the age of eight predict depression at the age of 10 (10). Poor sleep may impair memory, concentration, and interpersonal relationships. Generally, poor sleep may result in poor quality of life, as well as in poor mental and physical well-being. Therefore, low sleep quality results in increased health care costs in the community (11). People with low sleep quality appear to show signs of high arousal levels during sleep. The level of arousal is associated with both low sleep quality and sensory processing, which can be due to a lack of inhibition in the central nervous system (11)(12)(13)(14).
Recent research has shown a relationship between sleep problems and sensory processing patterns.
Sensory processing is the internal process of the central nervous system for receiving, organizing, and understanding sensory inputs (15). Differences in expected sensory processing patterns may be related to regulating and organizing the type and intensity of sensory inputs for adaptation to environmental requirements (16).
Among children without any disabilities, 5-10% have differences in sensory patterns (17). According to Dunn's sensory processing framework, a relationship exists between neural thresholds and behavioral responses (18). According to this framework, there are four sensory processing patterns: registration, sensation seeking, sensory sensitivity, and sensation avoiding. Based on these four patterns, it is possible to interpret the child's behavior from a sensory point of view (19).
The relationship between sensory processing and sleep has been investigated in children with autism, attention deficit hyperactivity disorder, and alcoholic fetal syndrome, as well as in normal school children, infants, and toddlers (20)(21)(22)(23)(24) (20). The results also revealed that sleep problems were associated with sensory processing deficits in children with alcoholic fetal syndrome (21,22), and that increased tactile sensitivity was related to sleep problems among normal school children (23). Vasak et al. (2015) reported correlations between increased seeking and shorter daytime sleep duration as well as between increased sensitivity and longer time to

Study design
This descriptive study was carried out using random cluster sampling.

Participants
At first, five districts of Tehran were selected (22, 5, 13, 14, and 8) randomly. Then, from each district, a school was selected, and after coordination with the schools, all parents of children aged 7 to 12 years old were invited to a free workshop at the school for participating in the study. Workshops were about students' sleep problems, which lasted about 3 hours. We distributed a demographic questionnaire and written consent forms among 300 parents. Our In sensory avoidance, a low neurological threshold, along with self-regulatory strategies and responses, is active. Sensory sensitivity is a pattern of sensory processing characterized by a low neurological threshold as well as self-regulating strategies and inactive responses (27).
Five categories and the cut-off score for the quadrants, which represent a set of capabilities for sensory integration, are much less than others (more than 2 standard deviations above the average), less than others (between 1 and 2 standard deviations above the average), much like others (about 1 standard deviation from the average), more than others (between 1 and 2 standard deviations below the average), and much more than others (more than 2 standard deviations below the average) (28).
In this study, we merged the categories one and two (much less than others and less than others) and the categories four and five (more and much more than

Data analysis
We used the Spearman correlation coefficient to examine the relationship between the quadrant scores of the sensory profile with the scores of the different sections and the total score of sleep habits.
To compare the sensory quadrants, the children were divided into two groups of normal sleep and sleep disorders based on the cut-off point> 42, which indicated sleep disorders. In order to examine the difference in the three parts, as well as others, less and much less than others, and more and much more than others, chi-square (χ2) was used in the two groups of children. Regarding the non-normal distribution of the variables, the Mann-Whitney U test was used to examine the difference between the sensory quadrants and to compare means in the two groups.

Results
The demographic information of the 231 children was analyzed and is summarized in Table 1.
According to Table 2, there was a moderate negative relationship between the total sleep score and sensory processing patterns in each of the four quadrants (p <0.001).
The sensory processing patterns in all the three sections were significantly different in the both groups based on the thex2 test (Table 3). In the Mann-Whitney U test, the mean was significantly different in all the four quadrants at p <0.001 (Table 4).  Iran J Child Neurol. Summer 2020 Vol. 14 No. 3

In conclusion
There is a moderate correlation between the high neurological threshold (poor sensory registration and sensory seeking) and the low neurological threshold (sensory sensitivity and sensory avoiding) with sleep quality and habits in primary school children in Iran. These findings suggest that children with sleep problems should be precisely evaluated in terms of the sensory processing patterns to improve their performance and increase their quality of life.

Acknowledgement
The project was financially supported by the Shahid Beheshti University of Medical Sciences.

Author Contributions
Study concept and design: Samira Rajaei and Dr.

Conflicts of Interest
The authors report no declaration of interest.